An argument
 A set of propositions, the premises, whose truth is intended to support or prove the truth of another set of propositions, the conclusion(s).10

A proposition
 Any description of a state of affairs. These may be either statements or depictions.11

A valid argument
 A deductive argument such that it is logically impossible for the premises to be true and the conclusion false.12

A sound argument
 A valid argument with true premises.12

A cogent nondeductive argument
 An argument whose premises support, but do not prove the truth, of their conclusions.12

A fallacy
 Any persuasive but unreliable form of argument.12

An enthymeme
 “Any argument in which one or more of its core propositions (a premise or conclusion) is not stated explicitly, but is merely assumed implicitly to be part of the argument”.12
